Written by Ada’s Medical Knowledge Team
What is cystic fibrosis?
Cystic fibrosis (CF) is a genetic condition which primarily affects the lungs and pancreas, but which can also affect other parts of the body, including the liver, kidneys and intestines. The disease is caused by a defect in the CFTR gene which helps proteins produce and release the body’s secretions, causing these secretions to become thick and sticky. Additional symptoms may include salty skin, digestion problems and poor growth in children.
Cystic fibrosis can be detected at birth through routine testing, with symptoms first appearing in early childhood and gradually worsening over time. Treatment options are available to help manage the condition, but, in the majority of cases, life-expectancy is reduced.
Symptoms of cystic fibrosis
The signs and symptoms of cystic fibrosis generally begin to occur around 6-8 months after birth, though this can differ significantly from person to person. Symptoms tend to differ depending on age and can affect various areas of the body.
Digestive symptoms of CF
One of the main areas that the condition affects is the pancreas, a glandular organ located within the gastrointestinal tract, or gut. The pancreas usually produces enzyme-containing digestive secretions, which flow out of the pancreas and into the duodenum to help digest food. Cystic fibrosis can block the flow of these digestive secretions, affecting the way food is digested. This can lead to:
- Large, fatty and foul-smelling stools
- Bloating of the abdomen
- Malnutrition and poor growth
Lung symptoms of CF
Cystic fibrosis can also cause the lungs to create thicker than normal sputum, or phlegm. As a consequence, bacteria may become trapped in the airways, causing infection and inflammation. If this happens, symptoms may include:
- A persistent cough, typically accompanied by sputum
- Shortness of breath
- Recurrent chest infections
Newborns with cystic fibrosis may have long-lasting jaundice, as well as meconium ileus, a condition that causes the gut to become clogged with meconium. This is a dark, sticky substance produced shortly before birth, usually excreted as a newborn’s first stool. If the gut becomes clogged with meconium, this may require surgery to relieve.
Some people with CF may also develop secondary conditions such as diabetes, osteoporosis, liver problems and male infertility. The Ada app can help you check your symptoms. Download the free app or find out more about the how it works.
Causes of cystic fibrosis
Cystic fibrosis is one of the most common inherited disorders. It is caused by a defect in the CFTR gene on chromosome 7. The CFTR gene controls the way sodium and chloride (salt) ions move in and out of the body’s cells. In people with cystic fibrosis, the gene defect causes too much sodium to enter the cells, which, in turn, causes too much water to enter the cells, leaving too little outside. This leads to secretions from outside the cells to be too thick.
The CFTR gene can be affected by over a thousand different defects. The type of defect can affect the level of severity of cystic fibrosis.
How is cystic fibrosis inherited?
Cystic fibrosis is an autosomal recessive disorder, meaning that to inherit the disorder, a person must receive two faulty genes, one from each parent. People with just one cystic fibrosis gene are known as carriers and usually lead normal lives. They can, however, pass the cystic fibrosis gene onto their children.
Cystic fibrosis is far more common in people of white-European descent than in people from any other ethnic group. An estimated 30,000 people are currently living with the disorder in the United States, with approximately 1,000 new cases diagnosed each year.
Diagnosing cystic fibrosis
Cystic fibrosis is diagnosed following various tests. In the United States, 75 percent of people with the condition are diagnosed by the age of 2.
- Newborn screening: All US states and many countries in the world test newborn babies for CF as a matter of routine. This may involve a genetic test to check for a gene defect, and/or a blood test to screen for pancreatic problems.
- Sweat test: If CF is suspected after initial testing, a sweat test may be used to confirm the diagnosis. This test involves analysing a sweat sample to see how much salt it contains. An abnormally high level may indicate CF.
- Other tests: If CF is confirmed, other tests may be carried out to check for complications. These may include ultrasound scans, X-rays and a biopsy.
Cystic fibrosis treatment
Treating cystic fibrosis typically involves the work of a varied team of CF specialists, nurses, dieticians, respiratory therapists, physical therapists and social workers, among others. This is necessary in order to help treat the many and varied symptoms of the condition. While there is currently no cure, cystic fibrosis can be managed effectively in most cases.
The range of possible treatment methods for cystic fibrosis is large and depends upon the symptoms being experienced. The following should be considered a general overview of some of the most commonly used treatment methods, not an exhaustive list.
Pancreatic treatment methods
Most people with cystic fibrosis will experience difficulty properly digesting food. A dietician will outline a detailed nutrition plan, typically high in fats and carbohydrates, to help combat this. Enzyme supplements may also be necessary, normally with each meal.
Lung treatment methods
Physical therapy, specifically focused on the chest, is often necessary to help clear the airways of sputum. A physical therapist will demonstrate how this is done, so parents and carers can carry out the procedure at home. Typically, the child lies face-down, and a specialist chest-patting technique is applied, encouraging the mucus to be coughed up. Children and adults with cystic fibrosis are also generally encouraged to take part in as much physical activity as possible, such as running or swimming.
Antibiotics are also a common aspect of cystic fibrosis treatment. Many people with the condition will take regular long-term courses of the medication, particularly when chest infections develop. If an infection is severe, antibiotic medications taken intravenously may be necessary.
Other treatment options for lung-related problems include inhalers, the use of oxygen, which may be necessary overnight in some cases, as well as medications such as dornase alfa, ibuprofen and azithromycin.
In severe cases, if the condition fails to respond to treatment, a lung transplant may be required. If successful, this can provide significant relief, but, as all major surgical procedures, it carries a variety of risks.
Cystic fibrosis prevention
As a genetic condition, there is no way to prevent cystic fibrosis. In many countries, babies are screened shortly after birth to ensure that treatment is begun as early as possible.
For people concerned about the possibility of being a cystic fibrosis carrier, genetic counseling and testing are available. Testing can help identify the presence of a faulty gene and counseling can help people to better understand the consequences of testing, as well as the typical pattern of progression of the condition and the treatment options available.
To help prevent potentially harmful bacteria being passed on, people who already have cystic fibrosis should avoid spending time with other people with the condition, especially indoors. Bacteria, such as Burkholderia cepacia complex and Pseudomonas aeruginosa, pose little risk to people without CF, but can settle in the lungs and cause harm to those who do. Activities such as meeting, sharing rooms and sharing objects should, therefore, be avoided.
Cystic fibrosis prognosis
Through improved treatment methods and better understanding over the past few decades, the typical life expectancy of a person with cystic fibrosis has drastically improved and roughly 80 percent of children diagnosed with the condition survive into adulthood.
Cystic fibrosis, however, remains a serious, life-limiting condition. The prognosis typically differs from person to person, depending on the severity of the condition, the symptoms that are present, as well as the treatment options available. Today, many people with cystic fibrosis live into their late 30s and children diagnosed with the condition today are expected to live into their 40s or 50s. Mortality in childhood or early adulthood, however, is still possible.
Cystic fibrosis FAQs
Q: Is there a cure for cystic fibrosis?
A: No. Currently, there is no cure for cystic fibrosis. Although treatment methods and life-expectancy have greatly improved over the past few decades, the condition remains a lifelong condition.
Q: Is cystic fibrosis dominant or recessive?
A: Cystic fibrosis is an autosomal recessive disorder. This means that two copies of the faulty gene are required to pass on the condition, one from the mother and one from the father. If only one gene is inherited, that person becomes a carrier. They will typically live normal lives, but will be able to pass on the condition to others.
Q: Is cystic fibrosis contagious?
A: No, cystic fibrosis is not contagious. It is an inherited condition, meaning it can only be passed on genetically. However, if a person with cystic fibrosis develops a bacterial or viral lung infection, this is contagious to people with or without CF. To prevent passing on the infection, people with a contagious lung infection should take steps to limit their exposure to other people until the condition has resolved.